Putting the protection circuit* on the battery's negative pole is standard best practice (due to NMOS efficiency, and it not being a problem in the slightest), and the 50mΩ actually improves balancing. Please avoid making comments like this based on half knowledge.
[*] I do wish it were an actual full protection circuit. It isn't. Then again a run of the mill protection circuit commonly doesn't cover reversed polarity [between protector and cell], which is rather important for this specific appliation.
> Putting the protection circuit* on the battery's negative pole is standard best practice
Pointer? Especially since LiPol paralleling seems to want to use bus bars to minimize wiring resistance.
Admittedly my experience is all about avoiding parallel LiPol batteries ...
https://www.ti.com/lit/gpn/bq77908a
https://www.diodes.com/assets/Datasheets/products_inactive_d...
Look at the reference circuits, it's a pair of antiserial NMOS on the negative pole.
(Those 2 protection circuits are at the opposite ends of complexity & features)
To be clear, using 2 PMOS on the positive pole is also quite common, my choice of words with "standard best practice" might be a bit misleading.
> use bus bars to minimize wiring resistance.
Those come after the protection circuit, there should always be 2 MOSFETs in series with the individual Li-Ion cell in a design like this (specifically: user swappable cell).
(Protecting paralleled cells together is kinda nonsensical because you also want to protect them from each other, I don't think I've ever seen a 2P combined protection circuit.)
Those datasheets show creating a series pack/cell. They don't show the circuitry to then parallel the packs together.
I guess I need to do more research on this.
> Those datasheets show creating a series pack/cell.
You seem to only have looked at the TI one, the Diodes one is for a single cell.
& if the cells are "permanently" connected in a pack, you wouldn't have individual cell protection and just have them properly balanced before connecting them in factory.
> parallel the packs together
You parallel cells, not packs.